Print View Posted on: 02 May 2013
A graduate student inhaled a mixture of U-233 and U-238 while working in a lab grinding a compound of uranium octoxide. The student used a glove box instead of a hood with a high-efficiency particulate air (HEPA) filter, contrary to the University of Nevada Las Vegas approved procedure. This happened twice, possibly between October 1, 2011 and April 1, 2012. The first bioassay, based on an inhalation date of October 1, 2011, resulted in a dose of 177.2 mSv (17.72 rem) total. When the inhalation date was assumed to be April 1, 2012, the result was 55.2 mSv (5.52 rem). The student will be given a third bioassay on September 5, 2012, that will involve a low-energy chest count to detect Th-234, and an organ count to detect any uranium in the kidneys. The student has been restricted from all lab work since April. UPDATE 2013 04 25: The State of Nevada reported that all of the activity ratios are consistent with that of natural uranium, supporting the conclusion that the source of the exposure is natural uranium from a non-occupational origin. NRC EN48261.